Five projects will be investigated. 1. A coordinated analysis of structure-function relationships of the glycoprotein fibronectin, using the techniques of protein chemistry, monoclonal antibodies and recombinant DNA. 2. Development of retroviruses as vectors for cloning cDNAs and expressing cDNAs in eucaryotic cells. Use of these vectors to investigate the mechanism of oncogenic transformation. 3. Cloning of cDNA for Na+/K+ATPase, introduction of the cloned sequences into cells and analysis of the effects of regulated expression of the ATPase on cells. 4. Analyses of the processing of the carbohydrate side-chains of glycoproteins and the possible biological roles of different forms of these side-chains. 5. Studies of the distribution, structure and function of microtubule-associated proteins in different cell types and states (e.g., mitosis) using recently developed methods for the direct analysis of cytoplasmic microtubules. These studies will lead to a deeper knowledge of proteins of the extracellular matrix surface membrane and cytoskeleton which is necessary for understanding how alterations in these are involved in oncogenic transformation.